Water-Assisted Delamination and Lithium Leaching for Recycling of Spent LiFePO4 Batteries

Abstract The large-scale retirement of spent LiFePO4 (SLFP) batteries with high market share requires the development of green and economically viable techniques for high-efficiency recycling of battery components. Here, we report a simple approach using water as the delamination and leaching reagent to recycle LiFePO4, graphite, Al/Cu foils, separators, and Li/F elements from the disassembled SLFP, enabling comprehensive resource recovery. Importantly, it was found that under the given experimental conditions, immersion of the LiFePO4 cathode and graphite anode in water increases the pH of the water solution from an initial value of ∼6.5 to ∼8.2 and ∼11.2, respectively, due to hydrolysis reactions of Li-containing substances. This alkaline solution environment effectively inhibits the materials’ corrosion by the produced HF, thus alleviating the generation of impurities. The results demonstrate that almost 100% of LiFePO4 and graphite with high purity can be exfoliated and recovered from the Al and Cu foil, respectively. During water-assisted delamination, Li and F elements in the cathode, anode, and separator were efficiently leached into water solution, enabling their recycling in the form of Li2CO3 and CaF2 with a recovering efficiency of 97.5% and 93.0%, respectively. This work would be helpful for comprehensive resource recovery of SLFP after battery disassembly.